FAQ: imc Hardware
- Why can't I find my imc CANSAS module on the CAN-bus?
Module not found
I can't find my imc CANSAS module on the CAN-bus
1.) Is the CAN-bus is terminated correctly?
Both ends must be terminated with a terminator (124 ohms according to CiA). (See Figure 1) If the module or instrument has only a CAN-bus connection, e.g., imc CRONOS-PL, then the termination should be made via a Y-cable and a terminator.
2.) Is each module set to the same transfer speed/baud rate?
All CAN-bus participants/modules being operated at a given node must be set to the same baud rate or else communication between the participants in the bus is not possible.
3.) Does the set baud rate and cable cross-section size match the cable length?
The transfer rate on the bus is dependent on the cable length, the cable cross-section and the number of nodes. The greater the cable length, the lower the possible transmission rate will be and a larger cable cross-section must be selected. (see Figure 2)
For more information, see the current imc CANSAS Manual
- Which version of imc CANSAS supports Kvaser Leaf SemiPro HS?
The interface is supported by the imc CANSAS Version 1.9 R4.
- Why doesn't the shunt calibration in my CANSAS module function correctly?
CANSAS and shunt calibration
The shunt calibration in my CANSAS module doesn't function correctly.
When performing a shunt calibration, channels that are set for half or quarter bridge measurement, cannot be open. Otherwise, during shunt calibration, incorrect readings will occur.
We therefore recommend to not set wired channels on the voltage measurement with maximum range or to not transmit over these channels (change CANSAS software to "without CAN message")
- How do I install my Kvaser interface (supplied by imc) so I can use it with imc CANSAS?
Insert the supplied driver CD and follow the installation instructions. Alternatively, you can also download the driver at the following link:
Only after the driver is installed should you connect the interface to the PC.
After the connection to the PC, the Windows Wizard will appear and display “Found New Hardware”. Since you have already installed all the necessary driver data, you need only click through the menu. Windows detects and connects the driver data in this step automatically.
In the last step, the interface in the imc CANSAS software can be found under Extras -> Interface Activate. Then, click on “board”:
KVASER GmbH ???(USB/PCI/PXI/ExpressCard/PCMCIA)
Then, check the box next to “(re)activate interface”
- I installed the driver for the imc CAN/USB adapter, but my interface is not detected! Why?
Up to the end of 2014, the imc CAN/USB adapter was supplied. At the end of the imc CANSAS installation, the dialog refers to the driver of this interface.
How you set up the Kvaser Leaf SemiPro HS interface for the imc CANSAS is described in the FAQ below.
- Why am I receiving implausible measurement values from my test system?
Implausible measurement values
I am receiving implausible measurement values from my test system.
Often times the problem can be traced to inadequate grounding of the device or the shielding on the signal wires. Through potential differences between the modules, and other connected devices, such as a laptop, BUSDAQ, etc., there can be compensation currents that can cause disturbances, and in the worst case, could destroy the module.
1. Grounding of the CANSAS module
Because it is anodized, the aluminum case itself is, generally, poorly conductive. Therefore, the locking bolts of the DSUB connector sockets should be used for grounding the device.
2. Shielding on the signal wires
Basically, to stay within the limits with respect to EMC and EMI, the use of shielded and grounded cables are necessary. In many cases, the use of a cost-effective, multi-conductor and simple shielded cable (also for multiple channels) is sufficient. (see Figure 1)
However, it may be necessary in other cases, to use double shielded cable. That is, common grounded (CHASSIS) and jacketed, within which individual (also more) coaxial cables are placed.
In particular, to avoid increased interference (noise), this process may be necessary if under the following conditions:
- "Higher" internal resistance of the signal source (> 100 Ohms)
- Signal sources not grounded (isolated or high impedance over CHASSIS and/or ground reference of the supply)
(see Figure 2)
3. Grounding from the CAN-Bus
Long CAN bus wires between the grounded module and the CAN data logger (device) can cause compensation currents on the bus. Therefore the CAN-bus shielding should only be opened at one end.
For more information, see the CANSAS Manual Version 1.6, section 5.4
- I ordered an imc USB Interface and I received a Kvaser Leaf SemiPro HS Interface for my imc CANSAS. Is this a mistake?
No. At the end of 2014, the imc CAN/USB interface was replaced by the Kvaser Leaf SemiPro HS Interface, which is currently the best on the market.